This cover reflects difficulties encountered on the first, and only,International Sky Train mail delivery between the US and Cuba.The difficulties are explained in the following enclosure.

The special stamps referred to above were Scott C16.They were prepared by overprinting a 10c printing of the 1931 airmail with a red 10c surcharge:PRIMER TREN AEREOINTERNACIONAL 1935

O'Meara y du Pont +10c

The stamps are believed to have some forgeries.Scott lists a double overprint which is believed to be genuinehowever the review of the discovered sheet was enver completed.

The covers also are believed to have been faked.I do note that this cover does not have the number 148 insertedin the space provided on the stamp signed by the pilots.

Ref: Jaques, Robert, "Miami to Havana -- by Glider"APJ, May 1980, pp.278-279, ill.Account of the first (and only one ever) international sky trainflight which took place 18 May 1935 from Miamito Havana and was piloted by O'Meara and Dupont.